1. Some members were not receiving emails sent from XJbikes.com. For example: "Forgot your password?" function to reset your password would not send email to some members. I believe this has been resolved now. Please use "Contact Us" form (see page footer link) if you still have email issues. SnoSheriff

    Hello Guest. You have limited privileges and you can't "SEARCH" the forums. Please "Log In" or "Sign Up" for additional functionality. Click HERE to proceed.

Mixture Screw/Colortune Question...82XJ650

Discussion in 'XJ Technical Chat' started by rocs82650, Feb 3, 2013.

  1. rocs82650

    rocs82650 Well-Known Member

    Messages:
    2,663
    Likes Received:
    356
    Trophy Points:
    83
    Location:
    Middle Tennessee
    I need to get this right. I don't see a color change in the Colortune plug. Valves are in spec. Carbs sync'd. Bike starts and idles at 1050rpms. Mixture screws set at 3 turns out. Yics tool installed. Colortune plug installed. As I turn the mixture screw out the rpms slowly start to increase. Is it at this point that chamber is rich and I should turn the screw back in until the bike returns to normal idle? Do this for all four then sync the carbs again? Then plug chop and make adjustments as needed? Thanks.

    Gary
     
  2. bigfitz52

    bigfitz52 Well-Known Member Premium Member

    Messages:
    21,283
    Likes Received:
    418
    Trophy Points:
    83
    Location:
    Rural SE Michigan 60 miles N of Motown
    No color change on any cylinder?

    What color were you seeing?
     
  3. LVSteve2011

    LVSteve2011 Member

    Messages:
    708
    Likes Received:
    1
    Trophy Points:
    18
    Location:
    Las Vegas NV
    To prove that I don't know it all, does the YICS tool need to be installed when adjusting the idle mixture? Since I don't know the answer to this question for sure, I theorize that with the YICS tool installed for this purpose, that it doesn't matter to the engine. But I could be wrong.
     
  4. bigfitz52

    bigfitz52 Well-Known Member Premium Member

    Messages:
    21,283
    Likes Received:
    418
    Trophy Points:
    83
    Location:
    Rural SE Michigan 60 miles N of Motown
    According to Yamaha the answer is yes.

    Yamaha's procedure for adjusting idle mixtures involved the use of an EGA, with YICS blocked; and the ColorTune is our "visual substitute" for the EGA.
     
  5. rocs82650

    rocs82650 Well-Known Member

    Messages:
    2,663
    Likes Received:
    356
    Trophy Points:
    83
    Location:
    Middle Tennessee
    BigFitz,

    I'm seeing powder blue. Pipes yellowing at top bend and plug electrodes still white at 3 turns out. Thanks.

    Gary
     
  6. bigfitz52

    bigfitz52 Well-Known Member Premium Member

    Messages:
    21,283
    Likes Received:
    418
    Trophy Points:
    83
    Location:
    Rural SE Michigan 60 miles N of Motown
    You're LEAN. If turning the pilots out isn't doing anything then your pilot circuits are still plugged up (or float levels horribly off.)

    Or you have a massive vacuum leak somewhere (or YICS isn't properly blocked, causing said vacuum leak.)
     
  7. rocs82650

    rocs82650 Well-Known Member

    Messages:
    2,663
    Likes Received:
    356
    Trophy Points:
    83
    Location:
    Middle Tennessee
    ok. thanks.

    Gary
     
  8. RickCoMatic

    RickCoMatic Well-Known Member

    Messages:
    13,843
    Likes Received:
    66
    Trophy Points:
    48
    Location:
    Massachusetts, Billerica
    Powder Blue is only Ideal for IDLE.
    You must add additional (Supplemental Richness) just beyond the Blue to prevent hesitation.

    The Supplemental Richness provides the Fuel needed to maintain combustion(s) during the BRIEF introduction of Fresh Air which precedes the Main Jet Supply.

    The Supplemental Richness involves turning the Mixture Screw OUT past the Blue about the width of a Nickel.

    The duration of Fresh Air preceding the Main Jet Supply is less than a second, but if not sufficiently Fueled, causes the Plant to hesitate.
     
  9. rocs82650

    rocs82650 Well-Known Member

    Messages:
    2,663
    Likes Received:
    356
    Trophy Points:
    83
    Location:
    Middle Tennessee
    Thanks.

    Gary
     
  10. LVSteve2011

    LVSteve2011 Member

    Messages:
    708
    Likes Received:
    1
    Trophy Points:
    18
    Location:
    Las Vegas NV
    Thank you Fitz for the answer to my question.
     

Share This Page